Table 3.
Predictors of Change in Physical Activity Between Waves 1 and 2: Results of Regression Analyses
| Model 1 (adjusted R2 = .37) | Model 2 (adjusted R2 = .38) | Model 3 (adjusted R2 = .38) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| β | SE | t | p-value | β | SE | t | p-value | β | SE | t | p-value | |
| PA (T0) | −0.71 | 0.06 | −12.87 | <.001 | −0.72 | 0.05 | −13.08 | < .001 | −0.72 | 0.06 | −12.95 | <.001 |
| PA intention (T0) | 0.13 | 0.05 | 2.66 | .008 | 0.13 | 0.05 | 2.51 | .012 | 0.12 | 0.05 | 2.44 | .015 |
| PA app use | 15.68 | 7.84 | 2.00 | .046 | 16.82 | 8.25 | 2.04 | .042 | 16.60 | 8.43 | 1.97 | .049 |
| PA app features | ||||||||||||
| Motivational | −183.00 | 105.2 | −1.74 | .083 | −178.7 | 108.5 | −1.65 | .99 | ||||
| Educational | 81.34 | 87.84 | 0.93 | .355 | 86.3 | 89.80 | 0.96 | .34 | ||||
| Gamification related | 235.40 | 90.75 | 2.59 | .010 | 214.9 | 95.57 | 2.25 | .025 | ||||
| Age | 13.36 | 10.19 | 1.31 | .19 | ||||||||
| Gender | −118.3 | 195.8 | −0.96 | .34 | ||||||||
| BMI | −18.98 | 17.45 | −1.09 | .28 | ||||||||
| Education | ||||||||||||
| Dummy 1 | −63.90 | 364.0 | −0.18 | .86 | ||||||||
| Dummy 2 | −57.52 | 322.1 | −0.18 | .86 | ||||||||
| Dummy 3 | −123.9 | 376.1 | −0.33 | .74 | ||||||||
| Dummy 4 | −493.7 | 705.9 | −0.70 | .49 | ||||||||
| Marital status | ||||||||||||
| Dummy 1 | −65.62 | 228.0 | −0.29 | .77 | ||||||||
| Dummy 2 | 403.5 | 424.8 | 0.95 | .34 | ||||||||
| Dummy 3 | −399.7 | 1,017.6 | −0.39 | .70 | ||||||||
| Income | ||||||||||||
| Dummy 1 | 363.1 | 443.9 | −1.16 | .25 | ||||||||
| Dummy 2 | 40.82 | 410.8 | 0.10 | .92 | ||||||||
| Dummy 3 | 206.3 | 434.5 | 0.47 | .64 | ||||||||
| Dummy 4 | 591.3 | 459.4 | 1.29 | .20 | ||||||||
| Dummy 5 | 589.9 | 437.2 | 1.35 | .18 | ||||||||
| Employment | ||||||||||||
| Dummy 1 | 346.6 | 361.1 | 0.96 | .34 | ||||||||
| Dummy 2 | −215.1 | 399.8 | −0.54 | .59 | ||||||||
| Ethnicity | ||||||||||||
| Dummy 1 | −179.9 | 366.3 | −0.49 | .62 | ||||||||
| Dummy 2 | −389.2 | 393.3 | −0.99 | .32 | ||||||||
| Dummy 3 | −380.6 | 514.0 | −0.74 | .46 | ||||||||
Dummy variables were created for categorical and ordinal variables (education: Dummy 1 was coded 1 for Associate’s degree, Dummy 2 for College Bachelor’s degree, Dummy 3 for Master‘s degree, and Dummy 4 for PhD; marital status: Dummy 1 was coded 1 for married, Dummy 2 for divorced, and Dummy 3 for widowed; income: Dummy 1 was coded 1 for $25,000–34,999, Dummy 2 for $35,000–49,999, Dummy 3 for $50,000–64,999, Dummy 4 for $65,000–79,999, and Dummy 5 for $80,000 and above; employment: Dummy 1 was coded 1 for self-employment and Dummy 2 for unemployment; ethnicity: Dummy 1 was coded 1 for Black/African American, Dummy 2 for Asian, and Dummy 3 for others).
β regression coefficient; BMI body mass index; PA physical activity; SE standard error; T0 Wave 1.